
Use your copy of the periodic table to help you answer the question.
Draw a diagram showing the arrangement of the valency electrons in one molecule of the covalent compound nitrogen trichloride. Use x to represent an electron from a nitrogen atom. Use O to represent an electron from a chlorine atom.

Important Questions on Cambridge IGCSE Exam Questions from Paper 3
Use your copy of the periodic table to help you answer the question.
Potassium and vanadium are elements in Period IV. State two differences in their physical properties.

Use your copy of the periodic table to help you answer the question.
Potassium and vanadium are elements in Period IV. Give two differences in their chemical properties.

Use your copy of the periodic table to help you answer the question.
Fluorine and astatine are halogens. Use your knowledge of the other halogens to predict the physical state of fluorine at r.t.p and physical state of astatine at r.t.p.

Use your copy of the periodic table to help you answer the question.
Fluorine and astatine are halogens. Use your knowledge of the other halogens to predict the similarities in chemical properties of fluorine and astatine.

Across the world, food safety agencies are investigating the presence of minute traces of the toxic hydrocarbon, benzene, in soft drinks. It is formed by the reduction of sodium benzoate by vitamin C.
Sodium benzoate is a salt. It has the formula . It can be made by neutralising benzoic acid using sodium hydroxide. Deduce the formula of benzoic acid.

Across the world, food safety agencies are investigating the presence of minute traces of the toxic hydrocarbon, benzene, in soft drinks. It is formed by the reduction of sodium benzoate by vitamin C.
Sodium benzoate is a salt. It has the formula . It can be made by neutralising benzoic acid using sodium hydroxide. Write the word equation for the reaction between benzoic acid and sodium hydroxide.

Across the world, food safety agencies are investigating the presence of minute traces of the toxic hydrocarbon, benzene, in soft drinks. It is formed by the reduction of sodium benzoate by vitamin C.
Sodium benzoate is a salt. It has the formula . It can be made by neutralising benzoic acid using sodium hydroxide. Name two other compounds that would react with benzoic acid to form sodium benzoate.

Benzene conatins of carbon and its relative molecular mass is . What is the percentage of hydrogen in benzene?
